When her mother dies under mysterious circumstances, a resourceful young school teacher must step into her mother’s job at the secluded Winston School for Children and try to uncover the reason behind her mother’s death.
It would be best to orientate the plot so as to make the MC take action for the sake of the future, not the past. In other words, instead of having her wanting to uncover the reason behind her mother’s death make her want to stop the killer or reason from happening again.
Also, best to redefine the inciting incident as a killing this will immediately spur the MC into action.
Lastly, “…mysterious circumstances…” mean very little in a logline, it’s the details of said circumstances that count. What is it that happens?